Source code
Revision control
Copy as Markdown
Other Tools
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
/*
* RSA key generation, public key op, private key op.
*/
#ifdef FREEBL_NO_DEPEND
#include "stubs.h"
#endif
#include "secerr.h"
#include "prclist.h"
#include "nssilock.h"
#include "prinit.h"
#include "blapi.h"
#include "mpi.h"
#include "mpprime.h"
#include "mplogic.h"
#include "secmpi.h"
#include "secitem.h"
#include "blapii.h"
/* The minimal required randomness is 64 bits */
/* EXP_BLINDING_RANDOMNESS_LEN is the length of the randomness in mp_digits */
/* for 32 bits platforts it is 2 mp_digits (= 2 * 32 bits), for 64 bits it is equal to 128 bits */
#define EXP_BLINDING_RANDOMNESS_LEN ((128 + MP_DIGIT_BIT - 1) / MP_DIGIT_BIT)
#define EXP_BLINDING_RANDOMNESS_LEN_BYTES (EXP_BLINDING_RANDOMNESS_LEN * sizeof(mp_digit))
/*
** Number of times to attempt to generate a prime (p or q) from a random
** seed (the seed changes for each iteration).
*/
#define MAX_PRIME_GEN_ATTEMPTS 10
/*
** Number of times to attempt to generate a key. The primes p and q change
** for each attempt.
*/
#define MAX_KEY_GEN_ATTEMPTS 10
/* Blinding Parameters max cache size */
#define RSA_BLINDING_PARAMS_MAX_CACHE_SIZE 20
/* exponent should not be greater than modulus */
#define BAD_RSA_KEY_SIZE(modLen, expLen) \
((expLen) > (modLen) || (modLen) > RSA_MAX_MODULUS_BITS / 8 || \
(expLen) > RSA_MAX_EXPONENT_BITS / 8)
struct blindingParamsStr;
typedef struct blindingParamsStr blindingParams;
struct blindingParamsStr {
blindingParams *next;
mp_int f, g; /* blinding parameter */
int counter; /* number of remaining uses of (f, g) */
};
/*
** RSABlindingParamsStr
**
** For discussion of Paul Kocher's timing attack against an RSA private key
** countermeasure to this attack, known as blinding, is also discussed in
** the Handbook of Applied Cryptography, 11.118-11.119.
*/
struct RSABlindingParamsStr {
/* Blinding-specific parameters */
PRCList link; /* link to list of structs */
SECItem modulus; /* list element "key" */
blindingParams *free, *bp; /* Blinding parameters queue */
blindingParams array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE];
/* precalculate montegomery reduction value */
mp_digit n0i; /* n0i = -( n & MP_DIGIT) ** -1 mod mp_RADIX */
};
typedef struct RSABlindingParamsStr RSABlindingParams;
/*
** RSABlindingParamsListStr
**
** List of key-specific blinding params. The arena holds the volatile pool
** of memory for each entry and the list itself. The lock is for list
** operations, in this case insertions and iterations, as well as control
** of the counter for each set of blinding parameters.
*/
struct RSABlindingParamsListStr {
PZLock *lock; /* Lock for the list */
PRCondVar *cVar; /* Condidtion Variable */
int waitCount; /* Number of threads waiting on cVar */
PRCList head; /* Pointer to the list */
};
/*
** The master blinding params list.
*/
static struct RSABlindingParamsListStr blindingParamsList = { 0 };
/* Number of times to reuse (f, g). Suggested by Paul Kocher */
#define RSA_BLINDING_PARAMS_MAX_REUSE 50
/* Global, allows optional use of blinding. On by default. */
/* Cannot be changed at the moment, due to thread-safety issues. */
static PRBool nssRSAUseBlinding = PR_TRUE;
static SECStatus
rsa_build_from_primes(const mp_int *p, const mp_int *q,
mp_int *e, PRBool needPublicExponent,
mp_int *d, PRBool needPrivateExponent,
RSAPrivateKey *key, unsigned int keySizeInBits)
{
mp_int n, phi;
mp_int psub1, qsub1, tmp;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&n) = 0;
MP_DIGITS(&phi) = 0;
MP_DIGITS(&psub1) = 0;
MP_DIGITS(&qsub1) = 0;
MP_DIGITS(&tmp) = 0;
CHECK_MPI_OK(mp_init(&n));
CHECK_MPI_OK(mp_init(&phi));
CHECK_MPI_OK(mp_init(&psub1));
CHECK_MPI_OK(mp_init(&qsub1));
CHECK_MPI_OK(mp_init(&tmp));
/* p and q must be distinct. */
if (mp_cmp(p, q) == 0) {
PORT_SetError(SEC_ERROR_NEED_RANDOM);
rv = SECFailure;
goto cleanup;
}
/* 1. Compute n = p*q */
CHECK_MPI_OK(mp_mul(p, q, &n));
/* verify that the modulus has the desired number of bits */
if ((unsigned)mpl_significant_bits(&n) != keySizeInBits) {
PORT_SetError(SEC_ERROR_NEED_RANDOM);
rv = SECFailure;
goto cleanup;
}
/* at least one exponent must be given */
PORT_Assert(!(needPublicExponent && needPrivateExponent));
/* 2. Compute phi = (p-1)*(q-1) */
CHECK_MPI_OK(mp_sub_d(p, 1, &psub1));
CHECK_MPI_OK(mp_sub_d(q, 1, &qsub1));
if (needPublicExponent || needPrivateExponent) {
CHECK_MPI_OK(mp_lcm(&psub1, &qsub1, &phi));
/* 3. Compute d = e**-1 mod(phi) */
/* or e = d**-1 mod(phi) as necessary */
if (needPublicExponent) {
err = mp_invmod(d, &phi, e);
} else {
err = mp_invmod(e, &phi, d);
}
} else {
err = MP_OKAY;
}
/* Verify that phi(n) and e have no common divisors */
if (err != MP_OKAY) {
if (err == MP_UNDEF) {
PORT_SetError(SEC_ERROR_NEED_RANDOM);
err = MP_OKAY; /* to keep PORT_SetError from being called again */
rv = SECFailure;
}
goto cleanup;
}
/* 4. Compute exponent1 = d mod (p-1) */
CHECK_MPI_OK(mp_mod(d, &psub1, &tmp));
MPINT_TO_SECITEM(&tmp, &key->exponent1, key->arena);
/* 5. Compute exponent2 = d mod (q-1) */
CHECK_MPI_OK(mp_mod(d, &qsub1, &tmp));
MPINT_TO_SECITEM(&tmp, &key->exponent2, key->arena);
/* 6. Compute coefficient = q**-1 mod p */
CHECK_MPI_OK(mp_invmod(q, p, &tmp));
MPINT_TO_SECITEM(&tmp, &key->coefficient, key->arena);
/* copy our calculated results, overwrite what is there */
key->modulus.data = NULL;
MPINT_TO_SECITEM(&n, &key->modulus, key->arena);
key->privateExponent.data = NULL;
MPINT_TO_SECITEM(d, &key->privateExponent, key->arena);
key->publicExponent.data = NULL;
MPINT_TO_SECITEM(e, &key->publicExponent, key->arena);
key->prime1.data = NULL;
MPINT_TO_SECITEM(p, &key->prime1, key->arena);
key->prime2.data = NULL;
MPINT_TO_SECITEM(q, &key->prime2, key->arena);
cleanup:
mp_clear(&n);
mp_clear(&phi);
mp_clear(&psub1);
mp_clear(&qsub1);
mp_clear(&tmp);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
SECStatus
generate_prime(mp_int *prime, int primeLen)
{
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
int piter;
unsigned char *pb = NULL;
pb = PORT_Alloc(primeLen);
if (!pb) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
goto cleanup;
}
for (piter = 0; piter < MAX_PRIME_GEN_ATTEMPTS; piter++) {
CHECK_SEC_OK(RNG_GenerateGlobalRandomBytes(pb, primeLen));
pb[0] |= 0xC0; /* set two high-order bits */
pb[primeLen - 1] |= 0x01; /* set low-order bit */
CHECK_MPI_OK(mp_read_unsigned_octets(prime, pb, primeLen));
err = mpp_make_prime_secure(prime, primeLen * 8, PR_FALSE);
if (err != MP_NO)
goto cleanup;
/* keep going while err == MP_NO */
}
cleanup:
if (pb)
PORT_ZFree(pb, primeLen);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
/*
* make sure the key components meet fips186 requirements.
*/
static PRBool
rsa_fips186_verify(mp_int *p, mp_int *q, mp_int *d, int keySizeInBits)
{
mp_int pq_diff;
mp_err err = MP_OKAY;
PRBool ret = PR_FALSE;
if (keySizeInBits < 250) {
/* not a valid FIPS length, no point in our other tests */
/* if you are here, and in FIPS mode, you are outside the security
* policy */
return PR_TRUE;
}
/* p & q are already known to be greater then sqrt(2)*2^(keySize/2-1) */
/* we also know that gcd(p-1,e) = 1 and gcd(q-1,e) = 1 because the
* mp_invmod() function will fail. */
/* now check p-q > 2^(keysize/2-100) */
MP_DIGITS(&pq_diff) = 0;
CHECK_MPI_OK(mp_init(&pq_diff));
/* NSS always has p > q, so we know pq_diff is positive */
CHECK_MPI_OK(mp_sub(p, q, &pq_diff));
if ((unsigned)mpl_significant_bits(&pq_diff) < (keySizeInBits / 2 - 100)) {
goto cleanup;
}
/* now verify d is large enough*/
if ((unsigned)mpl_significant_bits(d) < (keySizeInBits / 2)) {
goto cleanup;
}
ret = PR_TRUE;
cleanup:
mp_clear(&pq_diff);
return ret;
}
/*
** Generate and return a new RSA public and private key.
** Both keys are encoded in a single RSAPrivateKey structure.
** "cx" is the random number generator context
** "keySizeInBits" is the size of the key to be generated, in bits.
** 512, 1024, etc.
** "publicExponent" when not NULL is a pointer to some data that
** represents the public exponent to use. The data is a byte
** encoded integer, in "big endian" order.
*/
RSAPrivateKey *
RSA_NewKey(int keySizeInBits, SECItem *publicExponent)
{
unsigned int primeLen;
mp_int p = { 0, 0, 0, NULL };
mp_int q = { 0, 0, 0, NULL };
mp_int e = { 0, 0, 0, NULL };
mp_int d = { 0, 0, 0, NULL };
int kiter;
int max_attempts;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
int prerr = 0;
RSAPrivateKey *key = NULL;
PLArenaPool *arena = NULL;
/* Require key size to be a multiple of 16 bits. */
if (!publicExponent || keySizeInBits % 16 != 0 ||
BAD_RSA_KEY_SIZE((unsigned int)keySizeInBits / 8, publicExponent->len)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return NULL;
}
/* 1. Set the public exponent and check if it's uneven and greater than 2.*/
MP_DIGITS(&e) = 0;
CHECK_MPI_OK(mp_init(&e));
SECITEM_TO_MPINT(*publicExponent, &e);
if (mp_iseven(&e) || !(mp_cmp_d(&e, 2) > 0)) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
goto cleanup;
}
#ifndef NSS_FIPS_DISABLED
/* Check that the exponent is not smaller than 65537 */
if (mp_cmp_d(&e, 0x10001) < 0) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
goto cleanup;
}
#endif
/* 2. Allocate arena & key */
arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE);
if (!arena) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
goto cleanup;
}
key = PORT_ArenaZNew(arena, RSAPrivateKey);
if (!key) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
goto cleanup;
}
key->arena = arena;
/* length of primes p and q (in bytes) */
primeLen = keySizeInBits / (2 * PR_BITS_PER_BYTE);
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&d) = 0;
CHECK_MPI_OK(mp_init(&p));
CHECK_MPI_OK(mp_init(&q));
CHECK_MPI_OK(mp_init(&d));
/* 3. Set the version number (PKCS1 v1.5 says it should be zero) */
SECITEM_AllocItem(arena, &key->version, 1);
key->version.data[0] = 0;
kiter = 0;
max_attempts = 5 * (keySizeInBits / 2); /* FIPS 186-4 B.3.3 steps 4.7 and 5.8 */
do {
PORT_SetError(0);
CHECK_SEC_OK(generate_prime(&p, primeLen));
CHECK_SEC_OK(generate_prime(&q, primeLen));
/* Assure p > q */
/* NOTE: PKCS #1 does not require p > q, and NSS doesn't use any
* implementation optimization that requires p > q. We can remove
* this code in the future.
*/
if (mp_cmp(&p, &q) < 0)
mp_exch(&p, &q);
/* Attempt to use these primes to generate a key */
rv = rsa_build_from_primes(&p, &q,
&e, PR_FALSE, /* needPublicExponent=false */
&d, PR_TRUE, /* needPrivateExponent=true */
key, keySizeInBits);
if (rv == SECSuccess) {
if (rsa_fips186_verify(&p, &q, &d, keySizeInBits)) {
break;
}
prerr = SEC_ERROR_NEED_RANDOM; /* retry with different values */
} else {
prerr = PORT_GetError();
}
kiter++;
/* loop until have primes */
} while (prerr == SEC_ERROR_NEED_RANDOM && kiter < max_attempts);
cleanup:
mp_clear(&p);
mp_clear(&q);
mp_clear(&e);
mp_clear(&d);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
if (rv && arena) {
PORT_FreeArena(arena, PR_TRUE);
key = NULL;
}
return key;
}
mp_err
rsa_is_prime(mp_int *p)
{
int res;
/* run a Fermat test */
res = mpp_fermat(p, 2);
if (res != MP_OKAY) {
return res;
}
/* If that passed, run some Miller-Rabin tests */
res = mpp_pprime_secure(p, 2);
return res;
}
/*
* Factorize a RSA modulus n into p and q by using the exponents e and d.
*
* In: e, d, n
* Out: p, q
*
* See Handbook of Applied Cryptography, 8.2.2(i).
*
* The algorithm is probabilistic, it is run 64 times and each run has a 50%
* chance of succeeding with a runtime of O(log(e*d)).
*
* The returned p might be smaller than q.
*/
static mp_err
rsa_factorize_n_from_exponents(mp_int *e, mp_int *d, mp_int *p, mp_int *q,
mp_int *n)
{
/* lambda is the private modulus: e*d = 1 mod lambda */
/* so: e*d - 1 = k*lambda = t*2^s where t is odd */
mp_int klambda;
mp_int t, onetwentyeight;
unsigned long s = 0;
unsigned long i;
/* cand = a^(t * 2^i) mod n, next_cand = a^(t * 2^(i+1)) mod n */
mp_int a;
mp_int cand;
mp_int next_cand;
mp_int n_minus_one;
mp_err err = MP_OKAY;
MP_DIGITS(&klambda) = 0;
MP_DIGITS(&t) = 0;
MP_DIGITS(&a) = 0;
MP_DIGITS(&cand) = 0;
MP_DIGITS(&n_minus_one) = 0;
MP_DIGITS(&next_cand) = 0;
MP_DIGITS(&onetwentyeight) = 0;
CHECK_MPI_OK(mp_init(&klambda));
CHECK_MPI_OK(mp_init(&t));
CHECK_MPI_OK(mp_init(&a));
CHECK_MPI_OK(mp_init(&cand));
CHECK_MPI_OK(mp_init(&n_minus_one));
CHECK_MPI_OK(mp_init(&next_cand));
CHECK_MPI_OK(mp_init(&onetwentyeight));
mp_set_int(&onetwentyeight, 128);
/* calculate k*lambda = e*d - 1 */
CHECK_MPI_OK(mp_mul(e, d, &klambda));
CHECK_MPI_OK(mp_sub_d(&klambda, 1, &klambda));
/* factorize klambda into t*2^s */
CHECK_MPI_OK(mp_copy(&klambda, &t));
while (mpp_divis_d(&t, 2) == MP_YES) {
CHECK_MPI_OK(mp_div_2(&t, &t));
s += 1;
}
/* precompute n_minus_one = n - 1 */
CHECK_MPI_OK(mp_copy(n, &n_minus_one));
CHECK_MPI_OK(mp_sub_d(&n_minus_one, 1, &n_minus_one));
/* pick random bases a, each one has a 50% leading to a factorization */
CHECK_MPI_OK(mp_set_int(&a, 2));
/* The following is equivalent to for (a=2, a <= 128, a+=2) */
while (mp_cmp(&a, &onetwentyeight) <= 0) {
/* compute the base cand = a^(t * 2^0) [i = 0] */
CHECK_MPI_OK(mp_exptmod(&a, &t, n, &cand));
for (i = 0; i < s; i++) {
/* condition 1: skip the base if we hit a trivial factor of n */
if (mp_cmp(&cand, &n_minus_one) == 0 || mp_cmp_d(&cand, 1) == 0) {
break;
}
/* increase i in a^(t * 2^i) by squaring the number */
CHECK_MPI_OK(mp_exptmod_d(&cand, 2, n, &next_cand));
/* condition 2: a^(t * 2^(i+1)) = 1 mod n */
if (mp_cmp_d(&next_cand, 1) == 0) {
/* conditions verified, gcd(a^(t * 2^i) - 1, n) is a factor */
CHECK_MPI_OK(mp_sub_d(&cand, 1, &cand));
CHECK_MPI_OK(mp_gcd(&cand, n, p));
if (mp_cmp_d(p, 1) == 0) {
CHECK_MPI_OK(mp_add_d(&cand, 1, &cand));
break;
}
CHECK_MPI_OK(mp_div(n, p, q, NULL));
goto cleanup;
}
CHECK_MPI_OK(mp_copy(&next_cand, &cand));
}
CHECK_MPI_OK(mp_add_d(&a, 2, &a));
}
/* if we reach here it's likely (2^64 - 1 / 2^64) that d is wrong */
err = MP_RANGE;
cleanup:
mp_clear(&klambda);
mp_clear(&t);
mp_clear(&a);
mp_clear(&cand);
mp_clear(&n_minus_one);
mp_clear(&next_cand);
mp_clear(&onetwentyeight);
return err;
}
/*
* Try to find the two primes based on 2 exponents plus a prime.
*
* In: e, d and p.
* Out: p,q.
*
* Step 1, Since d = e**-1 mod phi, we know that d*e == 1 mod phi, or
* d*e = 1+k*phi, or d*e-1 = k*phi. since d is less than phi and e is
* usually less than d, then k must be an integer between e-1 and 1
* (probably on the order of e).
* Step 1a, We can divide k*phi by prime-1 and get k*(q-1). This will reduce
* the size of our division through the rest of the loop.
* Step 2, Loop through the values k=e-1 to 1 looking for k. k should be on
* the order or e, and e is typically small. This may take a while for
* a large random e. We are looking for a k that divides kphi
* evenly. Once we find a k that divides kphi evenly, we assume it
* is the true k. It's possible this k is not the 'true' k but has
* swapped factors of p-1 and/or q-1. Because of this, we
* tentatively continue Steps 3-6 inside this loop, and may return looking
* for another k on failure.
* Step 3, Calculate our tentative phi=kphi/k. Note: real phi is (p-1)*(q-1).
* Step 4a, kphi is k*(q-1), so phi is our tenative q-1. q = phi+1.
* If k is correct, q should be the right length and prime.
* Step 4b, It's possible q-1 and k could have swapped factors. We now have a
* possible solution that meets our criteria. It may not be the only
* solution, however, so we keep looking. If we find more than one,
* we will fail since we cannot determine which is the correct
* solution, and returning the wrong modulus will compromise both
* moduli. If no other solution is found, we return the unique solution.
*
* This will return p & q. q may be larger than p in the case that p was given
* and it was the smaller prime.
*/
static mp_err
rsa_get_prime_from_exponents(mp_int *e, mp_int *d, mp_int *p, mp_int *q,
mp_int *n, unsigned int keySizeInBits)
{
mp_int kphi; /* k*phi */
mp_int k; /* current guess at 'k' */
mp_int phi; /* (p-1)(q-1) */
mp_int r; /* remainder */
mp_int tmp; /* p-1 if p is given */
mp_err err = MP_OKAY;
unsigned int order_k;
MP_DIGITS(&kphi) = 0;
MP_DIGITS(&phi) = 0;
MP_DIGITS(&k) = 0;
MP_DIGITS(&r) = 0;
MP_DIGITS(&tmp) = 0;
CHECK_MPI_OK(mp_init(&kphi));
CHECK_MPI_OK(mp_init(&phi));
CHECK_MPI_OK(mp_init(&k));
CHECK_MPI_OK(mp_init(&r));
CHECK_MPI_OK(mp_init(&tmp));
/* our algorithm looks for a factor k whose maximum size is dependent
* on the size of our smallest exponent, which had better be the public
* exponent (if it's the private, the key is vulnerable to a brute force
* attack).
*
* since our factor search is linear, we need to limit the maximum
* size of the public key. this should not be a problem normally, since
* public keys are usually small.
*
* if we want to handle larger public key sizes, we should have
* a version which tries to 'completely' factor k*phi (where completely
* means 'factor into primes, or composites with which are products of
* large primes). Once we have all the factors, we can sort them out and
* try different combinations to form our phi. The risk is if (p-1)/2,
* (q-1)/2, and k are all large primes. In any case if the public key
* is small (order of 20 some bits), then a linear search for k is
* manageable.
*/
if (mpl_significant_bits(e) > 23) {
err = MP_RANGE;
goto cleanup;
}
/* calculate k*phi = e*d - 1 */
CHECK_MPI_OK(mp_mul(e, d, &kphi));
CHECK_MPI_OK(mp_sub_d(&kphi, 1, &kphi));
/* kphi is (e*d)-1, which is the same as k*(p-1)(q-1)
* d < (p-1)(q-1), therefor k must be less than e-1
* We can narrow down k even more, though. Since p and q are odd and both
* have their high bit set, then we know that phi must be on order of
* keySizeBits.
*/
order_k = (unsigned)mpl_significant_bits(&kphi) - keySizeInBits;
if (order_k <= 1) {
err = MP_RANGE;
goto cleanup;
}
/* for (k=kinit; order(k) >= order_k; k--) { */
/* k=kinit: k can't be bigger than kphi/2^(keySizeInBits -1) */
CHECK_MPI_OK(mp_2expt(&k, keySizeInBits - 1));
CHECK_MPI_OK(mp_div(&kphi, &k, &k, NULL));
if (mp_cmp(&k, e) >= 0) {
/* also can't be bigger then e-1 */
CHECK_MPI_OK(mp_sub_d(e, 1, &k));
}
/* calculate our temp value */
/* This saves recalculating this value when the k guess is wrong, which
* is reasonably frequent. */
/* tmp = p-1 (used to calculate q-1= phi/tmp) */
CHECK_MPI_OK(mp_sub_d(p, 1, &tmp));
CHECK_MPI_OK(mp_div(&kphi, &tmp, &kphi, &r));
if (mp_cmp_z(&r) != 0) {
/* p-1 doesn't divide kphi, some parameter wasn't correct */
err = MP_RANGE;
goto cleanup;
}
mp_zero(q);
/* kphi is now k*(q-1) */
/* rest of the for loop */
for (; (err == MP_OKAY) && (mpl_significant_bits(&k) >= order_k);
err = mp_sub_d(&k, 1, &k)) {
CHECK_MPI_OK(err);
/* looking for k as a factor of kphi */
CHECK_MPI_OK(mp_div(&kphi, &k, &phi, &r));
if (mp_cmp_z(&r) != 0) {
/* not a factor, try the next one */
continue;
}
/* we have a possible phi, see if it works */
if ((unsigned)mpl_significant_bits(&phi) != keySizeInBits / 2) {
/* phi is not the right size */
continue;
}
/* phi should be divisible by 2, since
* q is odd and phi=(q-1). */
if (mpp_divis_d(&phi, 2) == MP_NO) {
/* phi is not divisible by 4 */
continue;
}
/* we now have a candidate for the second prime */
CHECK_MPI_OK(mp_add_d(&phi, 1, &tmp));
/* check to make sure it is prime */
err = rsa_is_prime(&tmp);
if (err != MP_OKAY) {
if (err == MP_NO) {
/* No, then we still have the wrong phi */
continue;
}
goto cleanup;
}
/*
* It is possible that we have the wrong phi if
* k_guess*(q_guess-1) = k*(q-1) (k and q-1 have swapped factors).
* since our q_quess is prime, however. We have found a valid
* rsa key because:
* q is the correct order of magnitude.
* phi = (p-1)(q-1) where p and q are both primes.
* e*d mod phi = 1.
* There is no way to know from the info given if this is the
* original key. We never want to return the wrong key because if
* two moduli with the same factor is known, then euclid's gcd
* algorithm can be used to find that factor. Even though the
* caller didn't pass the original modulus, it doesn't mean the
* modulus wasn't known or isn't available somewhere. So to be safe
* if we can't be sure we have the right q, we don't return any.
*
* So to make sure we continue looking for other valid q's. If none
* are found, then we can safely return this one, otherwise we just
* fail */
if (mp_cmp_z(q) != 0) {
/* this is the second valid q, don't return either,
* just fail */
err = MP_RANGE;
break;
}
/* we only have one q so far, save it and if no others are found,
* it's safe to return it */
CHECK_MPI_OK(mp_copy(&tmp, q));
continue;
}
if ((unsigned)mpl_significant_bits(&k) < order_k) {
if (mp_cmp_z(q) == 0) {
/* If we get here, something was wrong with the parameters we
* were given */
err = MP_RANGE;
}
}
cleanup:
mp_clear(&kphi);
mp_clear(&phi);
mp_clear(&k);
mp_clear(&r);
mp_clear(&tmp);
return err;
}
/*
* take a private key with only a few elements and fill out the missing pieces.
*
* All the entries will be overwritten with data allocated out of the arena
* If no arena is supplied, one will be created.
*
* The following fields must be supplied in order for this function
* to succeed:
* one of either publicExponent or privateExponent
* two more of the following 5 parameters.
* modulus (n)
* prime1 (p)
* prime2 (q)
* publicExponent (e)
* privateExponent (d)
*
* NOTE: if only the publicExponent, privateExponent, and one prime is given,
* then there may be more than one RSA key that matches that combination.
*
* All parameters will be replaced in the key structure with new parameters
* Allocated out of the arena. There is no attempt to free the old structures.
* Prime1 will always be greater than prime2 (even if the caller supplies the
* smaller prime as prime1 or the larger prime as prime2). The parameters are
* not overwritten on failure.
*
* How it works:
* We can generate all the parameters from one of the exponents, plus the
* two primes. (rsa_build_key_from_primes)
* If we are given one of the exponents and both primes, we are done.
* If we are given one of the exponents, the modulus and one prime, we
* caclulate the second prime by dividing the modulus by the given
* prime, giving us an exponent and 2 primes.
* If we are given 2 exponents and one of the primes we calculate
* k*phi = d*e-1, where k is an integer less than d which
* divides d*e-1. We find factor k so we can isolate phi.
* phi = (p-1)(q-1)
* We can use phi to find the other prime as follows:
* q = (phi/(p-1)) + 1. We now have 2 primes and an exponent.
* (NOTE: if more then one prime meets this condition, the operation
* will fail. See comments elsewhere in this file about this).
* (rsa_get_prime_from_exponents)
* If we are given 2 exponents and the modulus we factor the modulus to
* get the 2 missing primes (rsa_factorize_n_from_exponents)
*
*/
SECStatus
RSA_PopulatePrivateKey(RSAPrivateKey *key)
{
PLArenaPool *arena = NULL;
PRBool needPublicExponent = PR_TRUE;
PRBool needPrivateExponent = PR_TRUE;
PRBool hasModulus = PR_FALSE;
unsigned int keySizeInBits = 0;
int prime_count = 0;
/* standard RSA nominclature */
mp_int p, q, e, d, n;
/* remainder */
mp_int r;
mp_err err = 0;
SECStatus rv = SECFailure;
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&d) = 0;
MP_DIGITS(&n) = 0;
MP_DIGITS(&r) = 0;
CHECK_MPI_OK(mp_init(&p));
CHECK_MPI_OK(mp_init(&q));
CHECK_MPI_OK(mp_init(&e));
CHECK_MPI_OK(mp_init(&d));
CHECK_MPI_OK(mp_init(&n));
CHECK_MPI_OK(mp_init(&r));
/* if the key didn't already have an arena, create one. */
if (key->arena == NULL) {
arena = PORT_NewArena(NSS_FREEBL_DEFAULT_CHUNKSIZE);
if (!arena) {
goto cleanup;
}
key->arena = arena;
}
/* load up the known exponents */
if (key->publicExponent.data) {
SECITEM_TO_MPINT(key->publicExponent, &e);
needPublicExponent = PR_FALSE;
}
if (key->privateExponent.data) {
SECITEM_TO_MPINT(key->privateExponent, &d);
needPrivateExponent = PR_FALSE;
}
if (needPrivateExponent && needPublicExponent) {
/* Not enough information, we need at least one exponent */
err = MP_BADARG;
goto cleanup;
}
/* load up the known primes. If only one prime is given, it will be
* assigned 'p'. Once we have both primes, well make sure p is the larger.
* The value prime_count tells us howe many we have acquired.
*/
if (key->prime1.data) {
int primeLen = key->prime1.len;
if (key->prime1.data[0] == 0) {
primeLen--;
}
keySizeInBits = primeLen * 2 * PR_BITS_PER_BYTE;
SECITEM_TO_MPINT(key->prime1, &p);
prime_count++;
}
if (key->prime2.data) {
int primeLen = key->prime2.len;
if (key->prime2.data[0] == 0) {
primeLen--;
}
keySizeInBits = primeLen * 2 * PR_BITS_PER_BYTE;
SECITEM_TO_MPINT(key->prime2, prime_count ? &q : &p);
prime_count++;
}
/* load up the modulus */
if (key->modulus.data) {
int modLen = key->modulus.len;
if (key->modulus.data[0] == 0) {
modLen--;
}
keySizeInBits = modLen * PR_BITS_PER_BYTE;
SECITEM_TO_MPINT(key->modulus, &n);
hasModulus = PR_TRUE;
}
/* if we have the modulus and one prime, calculate the second. */
if ((prime_count == 1) && (hasModulus)) {
if (mp_div(&n, &p, &q, &r) != MP_OKAY || mp_cmp_z(&r) != 0) {
/* p is not a factor or n, fail */
err = MP_BADARG;
goto cleanup;
}
prime_count++;
}
/* If we didn't have enough primes try to calculate the primes from
* the exponents */
if (prime_count < 2) {
/* if we don't have at least 2 primes at this point, then we need both
* exponents and one prime or a modulus*/
if (!needPublicExponent && !needPrivateExponent &&
(prime_count > 0)) {
CHECK_MPI_OK(rsa_get_prime_from_exponents(&e, &d, &p, &q, &n,
keySizeInBits));
} else if (!needPublicExponent && !needPrivateExponent && hasModulus) {
CHECK_MPI_OK(rsa_factorize_n_from_exponents(&e, &d, &p, &q, &n));
} else {
/* not enough given parameters to get both primes */
err = MP_BADARG;
goto cleanup;
}
}
/* Assure p > q */
/* NOTE: PKCS #1 does not require p > q, and NSS doesn't use any
* implementation optimization that requires p > q. We can remove
* this code in the future.
*/
if (mp_cmp(&p, &q) < 0)
mp_exch(&p, &q);
/* we now have our 2 primes and at least one exponent, we can fill
* in the key */
rv = rsa_build_from_primes(&p, &q,
&e, needPublicExponent,
&d, needPrivateExponent,
key, keySizeInBits);
cleanup:
mp_clear(&p);
mp_clear(&q);
mp_clear(&e);
mp_clear(&d);
mp_clear(&n);
mp_clear(&r);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
if (rv && arena) {
PORT_FreeArena(arena, PR_TRUE);
key->arena = NULL;
}
return rv;
}
static unsigned int
rsa_modulusLen(SECItem *modulus)
{
if (modulus->len == 0) {
return 0;
};
unsigned char byteZero = modulus->data[0];
unsigned int modLen = modulus->len - !byteZero;
return modLen;
}
/*
** Perform a raw public-key operation
** Length of input and output buffers are equal to key's modulus len.
*/
SECStatus
RSA_PublicKeyOp(RSAPublicKey *key,
unsigned char *output,
const unsigned char *input)
{
unsigned int modLen, expLen, offset;
mp_int n, e, m, c;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
if (!key || !output || !input) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
MP_DIGITS(&n) = 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&m) = 0;
MP_DIGITS(&c) = 0;
CHECK_MPI_OK(mp_init(&n));
CHECK_MPI_OK(mp_init(&e));
CHECK_MPI_OK(mp_init(&m));
CHECK_MPI_OK(mp_init(&c));
modLen = rsa_modulusLen(&key->modulus);
expLen = rsa_modulusLen(&key->publicExponent);
if (modLen == 0) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
rv = SECFailure;
goto cleanup;
}
/* 1. Obtain public key (n, e) */
if (BAD_RSA_KEY_SIZE(modLen, expLen)) {
PORT_SetError(SEC_ERROR_INVALID_KEY);
rv = SECFailure;
goto cleanup;
}
SECITEM_TO_MPINT(key->modulus, &n);
SECITEM_TO_MPINT(key->publicExponent, &e);
if (e.used > n.used) {
/* exponent should not be greater than modulus */
PORT_SetError(SEC_ERROR_INVALID_KEY);
rv = SECFailure;
goto cleanup;
}
/* 2. check input out of range (needs to be in range [0..n-1]) */
offset = (key->modulus.data[0] == 0) ? 1 : 0; /* may be leading 0 */
if (memcmp(input, key->modulus.data + offset, modLen) >= 0) {
PORT_SetError(SEC_ERROR_INPUT_LEN);
rv = SECFailure;
goto cleanup;
}
/* 2 bis. Represent message as integer in range [0..n-1] */
CHECK_MPI_OK(mp_read_unsigned_octets(&m, input, modLen));
/* 3. Compute c = m**e mod n */
#ifdef USE_MPI_EXPT_D
/* XXX see which is faster */
if (MP_USED(&e) == 1) {
CHECK_MPI_OK(mp_exptmod_d(&m, MP_DIGIT(&e, 0), &n, &c));
} else
#endif
CHECK_MPI_OK(mp_exptmod(&m, &e, &n, &c));
/* 4. result c is ciphertext */
err = mp_to_fixlen_octets(&c, output, modLen);
if (err >= 0)
err = MP_OKAY;
cleanup:
mp_clear(&n);
mp_clear(&e);
mp_clear(&m);
mp_clear(&c);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
/*
** RSA Private key operation (no CRT).
*/
static SECStatus
rsa_PrivateKeyOpNoCRT(RSAPrivateKey *key, mp_int *m, mp_int *c, mp_int *n,
unsigned int modLen)
{
mp_int d;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&d) = 0;
CHECK_MPI_OK(mp_init(&d));
SECITEM_TO_MPINT(key->privateExponent, &d);
/* 1. m = c**d mod n */
CHECK_MPI_OK(mp_exptmod(c, &d, n, m));
cleanup:
mp_clear(&d);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
/*
** RSA Private key operation using CRT.
*/
static SECStatus
rsa_PrivateKeyOpCRTNoCheck(RSAPrivateKey *key, mp_int *m, mp_int *c)
{
mp_int p, q, d_p, d_q, qInv;
/*
The length of the randomness comes from the papers:
*/
mp_int blinding_dp, blinding_dq, r1, r2;
unsigned char random_block[EXP_BLINDING_RANDOMNESS_LEN_BYTES];
mp_int m1, m2, h, ctmp;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&d_p) = 0;
MP_DIGITS(&d_q) = 0;
MP_DIGITS(&qInv) = 0;
MP_DIGITS(&m1) = 0;
MP_DIGITS(&m2) = 0;
MP_DIGITS(&h) = 0;
MP_DIGITS(&ctmp) = 0;
MP_DIGITS(&blinding_dp) = 0;
MP_DIGITS(&blinding_dq) = 0;
MP_DIGITS(&r1) = 0;
MP_DIGITS(&r2) = 0;
CHECK_MPI_OK(mp_init(&p));
CHECK_MPI_OK(mp_init(&q));
CHECK_MPI_OK(mp_init(&d_p));
CHECK_MPI_OK(mp_init(&d_q));
CHECK_MPI_OK(mp_init(&qInv));
CHECK_MPI_OK(mp_init(&m1));
CHECK_MPI_OK(mp_init(&m2));
CHECK_MPI_OK(mp_init(&h));
CHECK_MPI_OK(mp_init(&ctmp));
CHECK_MPI_OK(mp_init(&blinding_dp));
CHECK_MPI_OK(mp_init(&blinding_dq));
CHECK_MPI_OK(mp_init_size(&r1, EXP_BLINDING_RANDOMNESS_LEN));
CHECK_MPI_OK(mp_init_size(&r2, EXP_BLINDING_RANDOMNESS_LEN));
/* copy private key parameters into mp integers */
SECITEM_TO_MPINT(key->prime1, &p); /* p */
SECITEM_TO_MPINT(key->prime2, &q); /* q */
SECITEM_TO_MPINT(key->exponent1, &d_p); /* d_p = d mod (p-1) */
SECITEM_TO_MPINT(key->exponent2, &d_q); /* d_q = d mod (q-1) */
SECITEM_TO_MPINT(key->coefficient, &qInv); /* qInv = q**-1 mod p */
// blinding_dp = 1
CHECK_MPI_OK(mp_set_int(&blinding_dp, 1));
// blinding_dp = p - 1
CHECK_MPI_OK(mp_sub(&p, &blinding_dp, &blinding_dp));
// generating a random value
RNG_GenerateGlobalRandomBytes(random_block, EXP_BLINDING_RANDOMNESS_LEN_BYTES);
MP_USED(&r1) = EXP_BLINDING_RANDOMNESS_LEN;
memcpy(MP_DIGITS(&r1), random_block, sizeof(random_block));
// blinding_dp = random * (p - 1)
CHECK_MPI_OK(mp_mul(&blinding_dp, &r1, &blinding_dp));
//d_p = d_p + random * (p - 1)
CHECK_MPI_OK(mp_add(&d_p, &blinding_dp, &d_p));
// blinding_dq = 1
CHECK_MPI_OK(mp_set_int(&blinding_dq, 1));
// blinding_dq = q - 1
CHECK_MPI_OK(mp_sub(&q, &blinding_dq, &blinding_dq));
// generating a random value
RNG_GenerateGlobalRandomBytes(random_block, EXP_BLINDING_RANDOMNESS_LEN_BYTES);
memcpy(MP_DIGITS(&r2), random_block, sizeof(random_block));
MP_USED(&r2) = EXP_BLINDING_RANDOMNESS_LEN;
// blinding_dq = random * (q - 1)
CHECK_MPI_OK(mp_mul(&blinding_dq, &r2, &blinding_dq));
//d_q = d_q + random * (q-1)
CHECK_MPI_OK(mp_add(&d_q, &blinding_dq, &d_q));
/* 1. m1 = c**d_p mod p */
CHECK_MPI_OK(mp_mod(c, &p, &ctmp));
CHECK_MPI_OK(mp_exptmod(&ctmp, &d_p, &p, &m1));
/* 2. m2 = c**d_q mod q */
CHECK_MPI_OK(mp_mod(c, &q, &ctmp));
CHECK_MPI_OK(mp_exptmod(&ctmp, &d_q, &q, &m2));
/* 3. h = (m1 - m2) * qInv mod p */
CHECK_MPI_OK(mp_submod(&m1, &m2, &p, &h));
CHECK_MPI_OK(mp_mulmod(&h, &qInv, &p, &h));
/* 4. m = m2 + h * q */
CHECK_MPI_OK(mp_mul(&h, &q, m));
CHECK_MPI_OK(mp_add(m, &m2, m));
cleanup:
mp_clear(&p);
mp_clear(&q);
mp_clear(&d_p);
mp_clear(&d_q);
mp_clear(&qInv);
mp_clear(&m1);
mp_clear(&m2);
mp_clear(&h);
mp_clear(&ctmp);
mp_clear(&blinding_dp);
mp_clear(&blinding_dq);
mp_clear(&r1);
mp_clear(&r2);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
/*
** An attack against RSA CRT was described by Boneh, DeMillo, and Lipton in:
** "On the Importance of Eliminating Errors in Cryptographic Computations",
**
** As a defense against the attack, carry out the private key operation,
** followed up with a public key operation to invert the result.
** Verify that result against the input.
*/
static SECStatus
rsa_PrivateKeyOpCRTCheckedPubKey(RSAPrivateKey *key, mp_int *m, mp_int *c)
{
mp_int n, e, v;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&n) = 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&v) = 0;
CHECK_MPI_OK(mp_init(&n));
CHECK_MPI_OK(mp_init(&e));
CHECK_MPI_OK(mp_init(&v));
CHECK_SEC_OK(rsa_PrivateKeyOpCRTNoCheck(key, m, c));
SECITEM_TO_MPINT(key->modulus, &n);
SECITEM_TO_MPINT(key->publicExponent, &e);
/* Perform a public key operation v = m ** e mod n */
CHECK_MPI_OK(mp_exptmod(m, &e, &n, &v));
if (mp_cmp(&v, c) != 0) {
rv = SECFailure;
}
cleanup:
mp_clear(&n);
mp_clear(&e);
mp_clear(&v);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
static PRCallOnceType coBPInit = { 0, 0, 0 };
static PRStatus
init_blinding_params_list(void)
{
blindingParamsList.lock = PZ_NewLock(nssILockOther);
if (!blindingParamsList.lock) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
return PR_FAILURE;
}
blindingParamsList.cVar = PR_NewCondVar(blindingParamsList.lock);
if (!blindingParamsList.cVar) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
return PR_FAILURE;
}
blindingParamsList.waitCount = 0;
PR_INIT_CLIST(&blindingParamsList.head);
return PR_SUCCESS;
}
static SECStatus
generate_blinding_params(RSAPrivateKey *key, mp_int *f, mp_int *g, mp_int *n,
unsigned int modLen)
{
SECStatus rv = SECSuccess;
mp_int e, k;
mp_err err = MP_OKAY;
unsigned char *kb = NULL;
MP_DIGITS(&e) = 0;
MP_DIGITS(&k) = 0;
CHECK_MPI_OK(mp_init(&e));
CHECK_MPI_OK(mp_init(&k));
SECITEM_TO_MPINT(key->publicExponent, &e);
/* generate random k < n */
kb = PORT_Alloc(modLen);
if (!kb) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
goto cleanup;
}
CHECK_SEC_OK(RNG_GenerateGlobalRandomBytes(kb, modLen));
CHECK_MPI_OK(mp_read_unsigned_octets(&k, kb, modLen));
/* k < n */
CHECK_MPI_OK(mp_mod(&k, n, &k));
/* f = k**e mod n */
CHECK_MPI_OK(mp_exptmod(&k, &e, n, f));
/* g = k**-1 mod n */
CHECK_MPI_OK(mp_invmod(&k, n, g));
/* g in montgomery form.. */
CHECK_MPI_OK(mp_to_mont(g, n, g));
cleanup:
if (kb)
PORT_ZFree(kb, modLen);
mp_clear(&k);
mp_clear(&e);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
static SECStatus
init_blinding_params(RSABlindingParams *rsabp, RSAPrivateKey *key,
mp_int *n, unsigned int modLen)
{
blindingParams *bp = rsabp->array;
int i = 0;
/* Initialize the list pointer for the element */
PR_INIT_CLIST(&rsabp->link);
for (i = 0; i < RSA_BLINDING_PARAMS_MAX_CACHE_SIZE; ++i, ++bp) {
bp->next = bp + 1;
MP_DIGITS(&bp->f) = 0;
MP_DIGITS(&bp->g) = 0;
bp->counter = 0;
}
/* The last bp->next value was initialized with out
* of rsabp->array pointer and must be set to NULL
*/
rsabp->array[RSA_BLINDING_PARAMS_MAX_CACHE_SIZE - 1].next = NULL;
bp = rsabp->array;
rsabp->bp = NULL;
rsabp->free = bp;
/* precalculate montgomery reduction parameter */
rsabp->n0i = mp_calculate_mont_n0i(n);
/* List elements are keyed using the modulus */
return SECITEM_CopyItem(NULL, &rsabp->modulus, &key->modulus);
}
static SECStatus
get_blinding_params(RSAPrivateKey *key, mp_int *n, unsigned int modLen,
mp_int *f, mp_int *g, mp_digit *n0i)
{
RSABlindingParams *rsabp = NULL;
blindingParams *bpUnlinked = NULL;
blindingParams *bp;
PRCList *el;
SECStatus rv = SECSuccess;
mp_err err = MP_OKAY;
int cmp = -1;
PRBool holdingLock = PR_FALSE;
do {
if (blindingParamsList.lock == NULL) {
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
return SECFailure;
}
/* Acquire the list lock */
PZ_Lock(blindingParamsList.lock);
holdingLock = PR_TRUE;
/* Walk the list looking for the private key */
for (el = PR_NEXT_LINK(&blindingParamsList.head);
el != &blindingParamsList.head;
el = PR_NEXT_LINK(el)) {
rsabp = (RSABlindingParams *)el;
cmp = SECITEM_CompareItem(&rsabp->modulus, &key->modulus);
if (cmp >= 0) {
/* The key is found or not in the list. */
break;
}
}
if (cmp) {
/* At this point, the key is not in the list. el should point to
** the list element before which this key should be inserted.
*/
rsabp = PORT_ZNew(RSABlindingParams);
if (!rsabp) {
PORT_SetError(SEC_ERROR_NO_MEMORY);
goto cleanup;
}
rv = init_blinding_params(rsabp, key, n, modLen);
if (rv != SECSuccess) {
PORT_ZFree(rsabp, sizeof(RSABlindingParams));
goto cleanup;
}
/* Insert the new element into the list
** If inserting in the middle of the list, el points to the link
** to insert before. Otherwise, the link needs to be appended to
** the end of the list, which is the same as inserting before the
** head (since el would have looped back to the head).
*/
PR_INSERT_BEFORE(&rsabp->link, el);
}
/* We've found (or created) the RSAblindingParams struct for this key.
* Now, search its list of ready blinding params for a usable one.
*/
*n0i = rsabp->n0i;
while (0 != (bp = rsabp->bp)) {
#ifdef UNSAFE_FUZZER_MODE
/* Found a match and there are still remaining uses left */
/* Return the parameters */
CHECK_MPI_OK(mp_copy(&bp->f, f));
CHECK_MPI_OK(mp_copy(&bp->g, g));
PZ_Unlock(blindingParamsList.lock);
return SECSuccess;
#else
if (--(bp->counter) > 0) {
/* Found a match and there are still remaining uses left */
/* Return the parameters */
CHECK_MPI_OK(mp_copy(&bp->f, f));
CHECK_MPI_OK(mp_copy(&bp->g, g));
PZ_Unlock(blindingParamsList.lock);
return SECSuccess;
}
/* exhausted this one, give its values to caller, and
* then retire it.
*/
mp_exch(&bp->f, f);
mp_exch(&bp->g, g);
mp_clear(&bp->f);
mp_clear(&bp->g);
bp->counter = 0;
/* Move to free list */
rsabp->bp = bp->next;
bp->next = rsabp->free;
rsabp->free = bp;
/* In case there're threads waiting for new blinding
* value - notify 1 thread the value is ready
*/
if (blindingParamsList.waitCount > 0) {
PR_NotifyCondVar(blindingParamsList.cVar);
blindingParamsList.waitCount--;
}
PZ_Unlock(blindingParamsList.lock);
return SECSuccess;
#endif
}
/* We did not find a usable set of blinding params. Can we make one? */
/* Find a free bp struct. */
if ((bp = rsabp->free) != NULL) {
/* unlink this bp */
rsabp->free = bp->next;
bp->next = NULL;
bpUnlinked = bp; /* In case we fail */
PZ_Unlock(blindingParamsList.lock);
holdingLock = PR_FALSE;
/* generate blinding parameter values for the current thread */
CHECK_SEC_OK(generate_blinding_params(key, f, g, n, modLen));
/* put the blinding parameter values into cache */
CHECK_MPI_OK(mp_init(&bp->f));
CHECK_MPI_OK(mp_init(&bp->g));
CHECK_MPI_OK(mp_copy(f, &bp->f));
CHECK_MPI_OK(mp_copy(g, &bp->g));
/* Put this at head of queue of usable params. */
PZ_Lock(blindingParamsList.lock);
holdingLock = PR_TRUE;
(void)holdingLock;
/* initialize RSABlindingParamsStr */
bp->counter = RSA_BLINDING_PARAMS_MAX_REUSE;
bp->next = rsabp->bp;
rsabp->bp = bp;
bpUnlinked = NULL;
/* In case there're threads waiting for new blinding value
* just notify them the value is ready
*/
if (blindingParamsList.waitCount > 0) {
PR_NotifyAllCondVar(blindingParamsList.cVar);
blindingParamsList.waitCount = 0;
}
PZ_Unlock(blindingParamsList.lock);
return SECSuccess;
}
/* Here, there are no usable blinding parameters available,
* and no free bp blocks, presumably because they're all
* actively having parameters generated for them.
* So, we need to wait here and not eat up CPU until some
* change happens.
*/
blindingParamsList.waitCount++;
PR_WaitCondVar(blindingParamsList.cVar, PR_INTERVAL_NO_TIMEOUT);
PZ_Unlock(blindingParamsList.lock);
holdingLock = PR_FALSE;
(void)holdingLock;
} while (1);
cleanup:
/* It is possible to reach this after the lock is already released. */
if (bpUnlinked) {
if (!holdingLock) {
PZ_Lock(blindingParamsList.lock);
holdingLock = PR_TRUE;
}
bp = bpUnlinked;
mp_clear(&bp->f);
mp_clear(&bp->g);
bp->counter = 0;
/* Must put the unlinked bp back on the free list */
bp->next = rsabp->free;
rsabp->free = bp;
}
if (holdingLock) {
PZ_Unlock(blindingParamsList.lock);
}
if (err) {
MP_TO_SEC_ERROR(err);
}
*n0i = 0;
return SECFailure;
}
/*
** Perform a raw private-key operation
** Length of input and output buffers are equal to key's modulus len.
*/
static SECStatus
rsa_PrivateKeyOp(RSAPrivateKey *key,
unsigned char *output,
const unsigned char *input,
PRBool check)
{
unsigned int modLen;
unsigned int offset;
SECStatus rv = SECSuccess;
mp_err err;
mp_int n, c, m;
mp_int f, g;
mp_digit n0i;
if (!key || !output || !input) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
/* check input out of range (needs to be in range [0..n-1]) */
modLen = rsa_modulusLen(&key->modulus);
if (modLen == 0) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
offset = (key->modulus.data[0] == 0) ? 1 : 0; /* may be leading 0 */
if (memcmp(input, key->modulus.data + offset, modLen) >= 0) {
PORT_SetError(SEC_ERROR_INVALID_ARGS);
return SECFailure;
}
MP_DIGITS(&n) = 0;
MP_DIGITS(&c) = 0;
MP_DIGITS(&m) = 0;
MP_DIGITS(&f) = 0;
MP_DIGITS(&g) = 0;
CHECK_MPI_OK(mp_init(&n));
CHECK_MPI_OK(mp_init(&c));
CHECK_MPI_OK(mp_init(&m));
CHECK_MPI_OK(mp_init(&f));
CHECK_MPI_OK(mp_init(&g));
SECITEM_TO_MPINT(key->modulus, &n);
OCTETS_TO_MPINT(input, &c, modLen);
/* If blinding, compute pre-image of ciphertext by multiplying by
** blinding factor
*/
if (nssRSAUseBlinding) {
CHECK_SEC_OK(get_blinding_params(key, &n, modLen, &f, &g, &n0i));
/* c' = c*f mod n */
CHECK_MPI_OK(mp_mulmod(&c, &f, &n, &c));
}
/* Do the private key operation m = c**d mod n */
if (key->prime1.len == 0 ||
key->prime2.len == 0 ||
key->exponent1.len == 0 ||
key->exponent2.len == 0 ||
key->coefficient.len == 0) {
CHECK_SEC_OK(rsa_PrivateKeyOpNoCRT(key, &m, &c, &n, modLen));
} else if (check) {
CHECK_SEC_OK(rsa_PrivateKeyOpCRTCheckedPubKey(key, &m, &c));
} else {
CHECK_SEC_OK(rsa_PrivateKeyOpCRTNoCheck(key, &m, &c));
}
/* If blinding, compute post-image of plaintext by multiplying by
** blinding factor
*/
if (nssRSAUseBlinding) {
/* m = m'*g mod n */
CHECK_MPI_OK(mp_mulmontmodCT(&m, &g, &n, n0i, &m));
}
err = mp_to_fixlen_octets(&m, output, modLen);
if (err >= 0)
err = MP_OKAY;
cleanup:
mp_clear(&n);
mp_clear(&c);
mp_clear(&m);
mp_clear(&f);
mp_clear(&g);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
SECStatus
RSA_PrivateKeyOp(RSAPrivateKey *key,
unsigned char *output,
const unsigned char *input)
{
return rsa_PrivateKeyOp(key, output, input, PR_FALSE);
}
SECStatus
RSA_PrivateKeyOpDoubleChecked(RSAPrivateKey *key,
unsigned char *output,
const unsigned char *input)
{
return rsa_PrivateKeyOp(key, output, input, PR_TRUE);
}
SECStatus
RSA_PrivateKeyCheck(const RSAPrivateKey *key)
{
mp_int p, q, n, psub1, qsub1, e, d, d_p, d_q, qInv, res;
mp_err err = MP_OKAY;
SECStatus rv = SECSuccess;
MP_DIGITS(&p) = 0;
MP_DIGITS(&q) = 0;
MP_DIGITS(&n) = 0;
MP_DIGITS(&psub1) = 0;
MP_DIGITS(&qsub1) = 0;
MP_DIGITS(&e) = 0;
MP_DIGITS(&d) = 0;
MP_DIGITS(&d_p) = 0;
MP_DIGITS(&d_q) = 0;
MP_DIGITS(&qInv) = 0;
MP_DIGITS(&res) = 0;
CHECK_MPI_OK(mp_init(&p));
CHECK_MPI_OK(mp_init(&q));
CHECK_MPI_OK(mp_init(&n));
CHECK_MPI_OK(mp_init(&psub1));
CHECK_MPI_OK(mp_init(&qsub1));
CHECK_MPI_OK(mp_init(&e));
CHECK_MPI_OK(mp_init(&d));
CHECK_MPI_OK(mp_init(&d_p));
CHECK_MPI_OK(mp_init(&d_q));
CHECK_MPI_OK(mp_init(&qInv));
CHECK_MPI_OK(mp_init(&res));
if (!key->modulus.data || !key->prime1.data || !key->prime2.data ||
!key->publicExponent.data || !key->privateExponent.data ||
!key->exponent1.data || !key->exponent2.data ||
!key->coefficient.data) {
/* call RSA_PopulatePrivateKey first, if the application wishes to
* recover these parameters */
err = MP_BADARG;
goto cleanup;
}
SECITEM_TO_MPINT(key->modulus, &n);
SECITEM_TO_MPINT(key->prime1, &p);
SECITEM_TO_MPINT(key->prime2, &q);
SECITEM_TO_MPINT(key->publicExponent, &e);
SECITEM_TO_MPINT(key->privateExponent, &d);
SECITEM_TO_MPINT(key->exponent1, &d_p);
SECITEM_TO_MPINT(key->exponent2, &d_q);
SECITEM_TO_MPINT(key->coefficient, &qInv);
/* p and q must be distinct. */
if (mp_cmp(&p, &q) == 0) {
rv = SECFailure;
goto cleanup;
}
#define VERIFY_MPI_EQUAL(m1, m2) \
if (mp_cmp(m1, m2) != 0) { \
rv = SECFailure; \
goto cleanup; \
}
#define VERIFY_MPI_EQUAL_1(m) \
if (mp_cmp_d(m, 1) != 0) { \
rv = SECFailure; \
goto cleanup; \
}
/* n == p * q */
CHECK_MPI_OK(mp_mul(&p, &q, &res));
VERIFY_MPI_EQUAL(&res, &n);
/* gcd(e, p-1) == 1 */
CHECK_MPI_OK(mp_sub_d(&p, 1, &psub1));
CHECK_MPI_OK(mp_gcd(&e, &psub1, &res));
VERIFY_MPI_EQUAL_1(&res);
/* gcd(e, q-1) == 1 */
CHECK_MPI_OK(mp_sub_d(&q, 1, &qsub1));
CHECK_MPI_OK(mp_gcd(&e, &qsub1, &res));
VERIFY_MPI_EQUAL_1(&res);
/* d*e == 1 mod p-1 */
CHECK_MPI_OK(mp_mulmod(&d, &e, &psub1, &res));
VERIFY_MPI_EQUAL_1(&res);
/* d*e == 1 mod q-1 */
CHECK_MPI_OK(mp_mulmod(&d, &e, &qsub1, &res));
VERIFY_MPI_EQUAL_1(&res);
/* d_p == d mod p-1 */
CHECK_MPI_OK(mp_mod(&d, &psub1, &res));
VERIFY_MPI_EQUAL(&res, &d_p);
/* d_q == d mod q-1 */
CHECK_MPI_OK(mp_mod(&d, &qsub1, &res));
VERIFY_MPI_EQUAL(&res, &d_q);
/* q * q**-1 == 1 mod p */
CHECK_MPI_OK(mp_mulmod(&q, &qInv, &p, &res));
VERIFY_MPI_EQUAL_1(&res);
cleanup:
mp_clear(&n);
mp_clear(&p);
mp_clear(&q);
mp_clear(&psub1);
mp_clear(&qsub1);
mp_clear(&e);
mp_clear(&d);
mp_clear(&d_p);
mp_clear(&d_q);
mp_clear(&qInv);
mp_clear(&res);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
SECStatus
RSA_Init(void)
{
if (PR_CallOnce(&coBPInit, init_blinding_params_list) != PR_SUCCESS) {
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
return SECFailure;
}
return SECSuccess;
}
/* cleanup at shutdown */
void
RSA_Cleanup(void)
{
blindingParams *bp = NULL;
if (!coBPInit.initialized)
return;
while (!PR_CLIST_IS_EMPTY(&blindingParamsList.head)) {
RSABlindingParams *rsabp =
(RSABlindingParams *)PR_LIST_HEAD(&blindingParamsList.head);
PR_REMOVE_LINK(&rsabp->link);
/* clear parameters cache */
while (rsabp->bp != NULL) {
bp = rsabp->bp;
rsabp->bp = rsabp->bp->next;
mp_clear(&bp->f);
mp_clear(&bp->g);
}
SECITEM_ZfreeItem(&rsabp->modulus, PR_FALSE);
PORT_Free(rsabp);
}
if (blindingParamsList.cVar) {
PR_DestroyCondVar(blindingParamsList.cVar);
blindingParamsList.cVar = NULL;
}
if (blindingParamsList.lock) {
SKIP_AFTER_FORK(PZ_DestroyLock(blindingParamsList.lock));
blindingParamsList.lock = NULL;
}
coBPInit.initialized = 0;
coBPInit.inProgress = 0;
coBPInit.status = 0;
}
/*
* need a central place for this function to free up all the memory that
* free_bl may have allocated along the way. Currently only RSA does this,
* so I've put it here for now.
*/
void
BL_Cleanup(void)
{
RSA_Cleanup();
}
PRBool bl_parentForkedAfterC_Initialize;
/*
* Set fork flag so it can be tested in SKIP_AFTER_FORK on relevant platforms.
*/
void
BL_SetForkState(PRBool forked)
{
bl_parentForkedAfterC_Initialize = forked;
}